IP Addressing

Question 1

What is the first octet range and default subnet mask for Class A IP addresses?

Answer 1

First Octet Range: 1–127 Default Subnet Mask: 255.0.0.0 (/8)

Question 2

What is the first octet range and default subnet mask for Class B IP addresses?

Answer 2

First Octet Range: 128–191 Default Subnet Mask: 255.255.0.0 (/16)

Question 3

What is the first octet range and default subnet mask for Class C IP addresses?

Answer 3

First Octet Range: 192–223 Default Subnet Mask: 255.255.255.0 (/24)

Question 4

What is the first octet range and default subnet mask for Class D? and what is its main purpose?

Answer 4

First Octet Range: 224–239 Default Subnet Mask: None Purpose: Multicast routing

Question 5

What is the first octet range and default subnet mask for Class E? and what is its main purpose?

Answer 5

First Octet Range: 240–255 Default Subnet Mask: None Purpose: Research and development

Question 6

What is a classless subnet mask, and how does it differ from the default subnet masks used in IP address classes?

Answer 6

A classless subnet mask uses any subnet mask that does not match the default for Class A, B, or C (/8, /16, or /24)

Question 7

Who manages public IPv4 addresses globally?

Answer 7

The Internet Corporation for Assigned Names and Numbers (ICANN)

Question 8

Who manages public IPv4 addresses regionally?

Answer 8

Regional Internet Registries (RIRs) such as ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC

Question 9

What does a private IPv4 address allow devices to do?

Answer 9

Communicate within the same local network without using a public IP

Question 10

What is Network Address Translation (NAT) used for?

Answer 10

It translates private IPs to public IPs and vice versa, enabling communication between local and public networks

Question 11

What does RFC 1918 define?

Answer 11

The private IP address ranges for Class A, B, and C networks

Question 12

What is the private IP range for Class A?

Answer 12

10.0.0.0 – 10.255.255.255

Question 13

What is the private IP range for Class B?

Answer 13

172.16.0.0 – 172.31.255.255

Question 14

What is the private IP range for Class C?

Answer 14

192.168.0.0 – 192.168.255.255

Question 15

What is the specialized IP address assigned to the loopback interface? What is the loopback address used for?

Answer 15

127.0.0.1 (127 range) Used for internal testing and troubleshooting on the local host.

Question 16

What is the IP address range used by APIPA?

Answer 16

169.254.0.0 – 169.254.255.255 (169.254.x.x)

Question 17

What are the 4 key components of a fully configured network client?

Answer 17

IP address, Subnet mask, Default gateway, DNS server or WINS serve

Question 18

What does WINS (Windows Internet Name Service) do?

Answer 18

Identifies NetBIOS systems on a TCP/IP network, converts NetBIOS names to IP addresses, functions like DNS in Windows domains.

Question 19

What is BOOTP and what was its original purpose?

Answer 19

A legacy protocol that dynamically assigns IPs and allows a workstation to load a boot image over the network.

Question 20

What is ZeroConf and what features does it provide?

Answer 20

• Assigns IPv4 link-local addresses (like APIPA)
• Uses mDNS for name resolution without DNS
• Enables service discovery on the local network.

Question 21

How many bits are in an IPv6 address?

Answer 21

128 bits

Question 22

What are three ways to simplify an IPv6 address?

Answer 22

Remove leading zeros in each segment
replace consecutive zero-only segments with a double colon (::) — only once per address
condense four consecutive zeros into a single zero.

Question 23

What is anycast, and how does it support load balancing and failover?

Answer 23

Anycast assigns the same IP address to multiple servers; traffic is routed to the nearest or best-performing server, enabling automatic load balancing and failover.

Question 24

What are the two types of IPv6 unicast addresses and what do they start with?

Answer 24

Global Unicast: Routable on the internet, starts with 2000–3999
Link-Local: LAN-only, starts with FE80

Question 25

How does an IPv6 multicast address begin?

Answer 25

With FF in the first segment.

Question 26

What does Stateless Address Autoconfiguration (SLAAC) do in IPv6?

Answer 26

It lets a device auto-configure its own IP address without needing a central server like DHCP.

Question 27

What is EUI-64 used for in IPv6?

Answer 27

It allows a host to generate a unique 64-bit interface ID based on its MAC address.

Question 28

What is (NDP) used for in IPv6?

Answer 28

Neighbor Discovery Protocol helps devices discover each other, find other MAC addresses, and automatically configure themselves. It replaces several IPv4 functions like ARP and router discovery.

Question 29

What is NAT64 used for?

Answer 29

It lets IPv6-only devices talk to IPv4 servers by translating between IPv6 and IPv4 addresses.

Question 30

How many mandatory fields are in a TCP header and how large is it?

Answer 30

10 mandatory fields totaling 20 bytes.

Question 31

What are the key fields in a TCP header?

Answer 31

Source/Destination Ports, Sequence/Ack Numbers, Control Flags, Window Size, and Checksum.

Question 32

How many fields are in a UDP header and how large is it?

Answer 32

4 fields totaling 8 bytes.

Question 33

What’s the purpose of the IP header?

Answer 33

It carries addressing and routing info so packets can move across networks. – Layer 3

Question 34

What is the primary function of Network Address Translation (NAT)?

Answer 34

NAT translates private IP addresses into public IP addresses to conserve IPv4 address space.

Question 35

What does Port Address Translation (PAT) do differently from NAT?

Answer 35

PAT allows multiple devices to share a single public IP address by assigning unique port numbers to each session—enabling many-to-one translation.

Question 36

What is IPv6 tunneling and how does Teredo fit in?

Answer 36

IPv6 tunneling = encapsulates IPv6 packets inside IPv4 packets to traverse IPv4-only networks Teredo = a tunneling protocol for IPv6-over-IPv4, works behind NAT using UDP

Question 37

A network administrator is configuring a subnet with the network address of 192.168.10.0/28. What is the range of usable host IP addresses for this subnet?

Answer 37

192.168.10.1 to 192.168.10.14

Question 38

How does IPv6 Stateless Address Autoconfiguration (SLAAC) work, and what role do Router Advertisements (RAs) play?

Answer 38

Hosts use SLAAC to automatically configure IPv6 addresses. Routers send periodic RAs containing the network prefix and other config info. Hosts combine the prefix with their interface identifier to generate a valid IPv6 address.

Question 39

What is a DHCP scope?

Answer 39

A DHCP scope defines the range of IP addresses and related network settings (subnet mask, gateway, DNS, lease time) that a DHCP server can assign to devices on a subnet.

Question 40

What issues can arise from duplicate IP addresses on a network? 2/3

Answer 40

Devices may lose connectivity or experience intermittent network access. Packets may be misrouted or sent to the wrong device. Can cause ARP conflicts, broadcast storms, or application errors.

Question 41

What’s the best way to enable IPv4-only legacy devices to access IPv6-only external services in a dual stack network? Name protocol

Answer 41

Use a tunneling protocol like Teredo or ISATAP to encapsulate IPv6 traffic over IPv4.

Question 42

What’s the difference between SLAAC and EUI-64 in IPv6 addressing?

Answer 42

SLAAC automatically configure their own Network portion of an address EUI-64: A method used within SLAAC to generate the Host ID portion of the IPv6 address by modifying the device’s MAC address. SLAAC needs a method to create the second half of the IPv6 address. EUI-64 is just one of several ways to do that — it’s not required, but it was the original default.

Question 43

In CIDR notation, what’s the difference between network bits and host bits?

Answer 43

Network bits (the leftmost bits, defined by the CIDR prefix like /24) identify the network or subnet — all devices sharing these bits are on the same network. Host bits (the remaining bits on the right) identify individual devices (hosts) within that network.

Question 44

Why is static IP assignment or DHCP reservation preferred over dynamic assignment for printers?

Answer 44

Static assignment or reservations ensure printers always have the same IP, providing consistent network access and easier management, whereas dynamic IPs can change and disrupt printing services.